Natural gas differential pressure radial turbine power generation system

Abstract

The utility model discloses a natural gas differential pressure radial turbine power generation system which comprises a gas inlet pipeline, and the gas inlet end of the gas inlet pipeline is connected with a natural gas conveying pipeline. A first stop valve, a pressure regulating assembly and an expansion generator are arranged in the first pressure reducing pipeline in series; a second stop valve and a pressure regulating valve C are arranged in the second pressure reducing pipeline in series; the first pressure reduction pipeline and the second pressure reduction pipeline are connected in parallel, the air inlet ends of the first pressure reduction pipeline and the second pressure reduction pipeline are connected to the air outlet end of the air inlet pipeline, the air outlet end of the first pressure reduction pipeline is connected to the air outlet pipeline after passing through the cold energy utilization pipeline, and the air outlet end of the second pressure reduction pipeline is connected to the air outlet pipeline. Efficient conversion and utilization of energy are achieved through the high and low pressure difference and cold energy of natural gas in the pipeline.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas power generation equipment, in particular to a natural gas differential pressure radial turbine power generation system. Background Art

[0002] In the national natural gas pipeline network system, natural gas is delivered to users through a series of complex pipeline systems. In this process, pressure reduction is an indispensable part. As a hydrocarbon mixture, the temperature of natural gas will decrease as the pressure decreases during the pressure reduction process. For example, assuming that the temperature of natural gas at the inlet of the pipeline is 20 degrees, after the pressure reduction treatment, the temperature at the outlet may drop sharply to 0 degrees or even lower. This drastic change in temperature poses a severe challenge to the material and structure of the pipeline. Due to the decrease in temperature, the inside of the pipeline is prone to condensation into ice, which then forms an ice blockage phenomenon. Once frozen, it will seriously hinder the normal circulation of natural gas. In order to solve this problem, it is usually necessary to install heating tape on the pipeline. The function of the heating tape is to heat the pipeline through the electrothermal effect to prevent the natural gas from freezing during transportation; however, the heating process consumes a lot of electricity, which undoubtedly increases the operating cost, and also causes the high and low pressure difference of natural gas to be wasted, reducing energy utilization efficiency.

[0003] In addition to the ice blockage problem, pipeline failures can easily affect the stable transportation and safe use of natural gas. Since natural gas is flammable and explosive, once a pipeline fails, it may cause a serious safety accident. Therefore, daily maintenance and inspection of pipelines are particularly important. However, in the actual maintenance process, it is necessary to close some pipelines for maintenance work, which often affects the normal gas demand of users, so it is necessary to improve it. Utility Model Content

[0004] The purpose of the utility model is to provide a natural gas differential pressure radial turbine power generation system in view of the defects and shortcomings of the prior art. The system has a simple and reasonable structure and is easy to operate. By utilizing the high and low pressure differences and cold energy of the natural gas in the pipeline, efficient conversion and utilization of energy are achieved. At the same time, the stable transportation and safe use of natural gas are ensured through precise pressure regulation, non-return design and the provision of spare pipelines.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a natural gas differential pressure radial turbine power generation system, comprising an air intake pipeline, the air intake end of the air intake pipeline is connected to the natural gas transmission pipeline; a first pressure reducing pipeline, the first pressure reducing pipeline is provided with a first shut-off valve, a pressure regulating component and an expansion generator in series; a second pressure reducing pipeline, the second pressure reducing pipeline is provided with a second shut-off valve and a pressure regulating valve C in series; the first pressure reducing pipeline and the second pressure reducing pipeline are connected in parallel, the air intake ends of the first pressure reducing pipeline and the second pressure reducing pipeline are connected to the air outlet end of the air intake pipeline, the air outlet end of the first pressure reducing pipeline is connected to the air outlet pipeline after passing through a cold energy utilization pipeline, and the air outlet end of the second pressure reducing pipeline is connected to the air outlet pipeline.

[0007] Furthermore, a filter is serially arranged in the air intake pipeline.

[0008] Furthermore, a heat exchanger is provided in the cold energy utilization pipeline.

[0009] Furthermore, the first pressure reducing pipeline includes pipeline a and pipeline b, pipeline a is provided with a first shut-off valve and a pressure regulating assembly, pipeline b is provided with an expansion generator, the air inlet end of pipeline a is connected to the air outlet end of the air inlet pipeline, the air inlet end of pipeline b is connected to the air outlet end of pipeline a, and the air outlet end of pipeline b is connected to the air outlet pipeline after passing through the cold energy utilization pipeline.

[0010] Furthermore, an orifice flowmeter is also serially connected in the pipeline a.

[0011] Furthermore, the first pressure-reducing pipeline also includes a pipeline c, in which a pneumatic switching valve is arranged in series, and a handwheel is arranged on the pneumatic switching valve. The air inlet end of the pipeline c is connected to the air outlet end of the pipeline a, and the air outlet end of the pipeline c is respectively connected to the first connecting pipeline and the second connecting pipeline. The cold energy utilization pipeline is connected to the air outlet pipeline via the first connecting pipeline and the second connecting pipeline, and the pipeline c is connected to the air outlet pipeline via the second connecting pipeline.

[0012] Furthermore, a vent valve is provided in the second connecting pipeline.

[0013] Furthermore, the pressure regulating assembly includes a pressure regulating valve A, and the pressure regulating valve A is connected in parallel with a pressure regulating valve B.

[0014] Furthermore, the caliber of the pressure regulating valve A is larger than the caliber of the pressure regulating valve B.

[0015] Furthermore, a check valve is serially arranged in the air outlet pipeline.

[0016] The beneficial effects of the utility model are as follows: a natural gas differential pressure radial turbine power generation system described in the utility model is provided with a temperature gauge A and a filter in the air intake pipeline. The temperature gauge A is a visual temperature gauge, which is convenient for observing the temperature on site and transmitting the temperature remotely to the control room. The filter is used to filter impurities in the natural gas. The bottom end of the filter is provided with a drain valve A for draining sewage to discharge impurities in the natural gas. When the first pressure reducing pipeline is working normally, the first shut-off valve is opened and the second shut-off valve is closed. The natural gas passes through the first pressure reducing pipeline and is pressure-regulated by the pressure regulating component and then is pressure-reduced by the expansion generator to enable the expansion generator to generate electricity. The temperature of the natural gas after pressure reduction is reduced to generate usable cold energy, which is effectively utilized through the cold energy utilization pipeline. The cold energy utilization pipeline can be widely used in various occasions requiring a low-temperature environment, such as air-conditioning pipes used in the control room, which can introduce the cold energy generated in the process of natural gas pressure reduction into the control room to cool down the room. In the cold energy utilization pipeline, the heat exchanger is used to transfer the cold energy generated in the process of natural gas pressure reduction to the medium that needs to be cooled. Through the heat exchange process of the heat exchanger, the cold energy is effectively utilized, and at the same time, ice blockage in the pipeline is avoided, ensuring the smooth transportation of natural gas; the second pressure reduction pipeline is used as a backup route. When the first pressure reduction pipeline fails, the second cut-off valve is controlled to open and the first cut-off valve is closed. The natural gas is reduced in pressure through the second pressure reduction pipeline by the pressure regulating valve C and then discharged from the outlet end of the outlet pipeline. In order to ensure the one-way flow of natural gas and prevent backflow, a check valve is arranged in series in the outlet pipeline. The reduced-pressure natural gas is discharged from the outlet end of the outlet pipeline through the check valve and finally delivered to users who need natural gas; by utilizing the high and low pressure difference and cold energy of the natural gas in the pipeline, efficient conversion and utilization of energy is achieved. At the same time, through precise pressure regulation and check design, stable transportation and safe use of natural gas are ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model in the first viewing angle;

[0018] Figure 2 It is a structural schematic diagram of the utility model under a second viewing angle.

[0019] Figure 1-2 In: 1. Inlet pipeline; 11. Filter; 111. Drain valve A; 2. First pressure-reducing pipeline; 21. Pipeline a; 211. Orifice flowmeter; 212. First shut-off valve; 213. Pressure regulating valve A; 214. Pressure regulating valve B; 22. Pipeline b; 221. Expansion generator; 23. Pipeline c; 231. Pneumatic switch valve; 3. Second pressure-reducing pipeline; 31. Second shut-off valve; 32. Pressure regulating valve C; 4. Exhaust pipeline; 41. Check valve; 5. Pressure vessel tank; 51. Safety valve; 52. Drain valve B; 6. First connecting pipeline; 7. Second connecting pipeline; 71. Vent valve; 8. Cold energy utilization pipeline. DETAILED DESCRIPTION

[0020] The utility model is further described below in conjunction with the accompanying drawings.

[0021] like Figure 1-2 The natural gas differential pressure radial turbine power generation system shown in the figure comprises an air intake pipeline 1, the air intake end of the air intake pipeline 1 is connected to the natural gas transmission pipeline; the natural gas of the national natural gas pipeline network is transported to the air intake end of the air intake pipeline 1 through the natural gas transmission pipeline, and a temperature gauge A and a filter 11 are provided in the air intake pipeline 1. Preferably, the temperature gauge A is a visual temperature gauge, which is convenient for on-site temperature observation and temperature transmission to the control room. The filter 11 is used to filter impurities in the natural gas. The bottom end of the filter 11 is provided with a drain valve A111 for draining the natural gas. impurities in the gas are discharged; a first pressure-reducing pipeline 2, in which a first shut-off valve 212, a pressure regulating component and an expansion generator 221 are arranged in series, and the expansion generator 221 generates electricity by using the high and low pressure difference of the natural gas in the pipeline to realize the conversion and utilization of energy; a second pressure-reducing pipeline 3, in which a second shut-off valve 31 and a pressure regulating valve C32 are arranged in series; the first pressure-reducing pipeline 2 and the second pressure-reducing pipeline 3 are connected in parallel, and the air inlet ends of the first pressure-reducing pipeline 2 and the second pressure-reducing pipeline 3 are connected to the air outlet end of the air inlet pipeline 1, and the first pressure-reducing pipeline The outlet end of the first pressure reducing pipeline 2 is connected to the outlet pipeline 4 after passing through the cold energy utilization pipeline, and the outlet end of the second pressure reducing pipeline 3 is connected to the outlet pipeline 4. Preferably, in this embodiment, a heat exchanger is provided in the cold energy utilization pipeline. When the first pressure reducing pipeline 2 works normally, the first shut-off valve 212 is opened and the second shut-off valve 31 is closed. The natural gas passes through the first pressure reducing pipeline 2 and is pressure-regulated by the pressure regulating component and then is pressure-reduced by the expansion generator 221, so that the expansion generator 221 generates electricity. The temperature of the natural gas after pressure reduction is reduced, and usable cold energy is generated. The cold energy is effectively utilized through the cold energy utilization pipeline. The cold energy utilization pipeline can be widely used in various occasions requiring a low temperature environment, such as an air-conditioning pipeline for a control room, which can introduce the cold energy generated in the process of natural gas pressure reduction into the control room to play a role in cooling. In the cold energy utilization pipeline, the heat exchanger is used to transfer the cold energy generated in the process of natural gas pressure reduction to the medium that needs to be cooled. Through the heat exchange process of the heat exchanger, the cold energy is effectively utilized, and at the same time, ice blockage in the pipeline is avoided, ensuring the smooth transportation of natural gas.

[0022] The second pressure-reducing pipeline 3 is used as a backup route. When the first pressure-reducing pipeline 2 fails, the second shut-off valve 31 is controlled to be opened and the first shut-off valve 212 is controlled to be closed. The natural gas passes through the second pressure-reducing pipeline 3 and is reduced in pressure by the pressure regulating valve C32, and is then discharged from the gas outlet end of the gas outlet pipeline 4. Preferably, in this embodiment, in order to ensure the unidirectional flow of natural gas and prevent backflow, a check valve 41 is serially arranged in the gas outlet pipeline 4. The reduced-pressure natural gas is discharged from the gas outlet end of the gas outlet pipeline 4 through the check valve 41, and is finally delivered to users who need natural gas. By utilizing the high and low pressure difference and cold energy of the natural gas in the pipeline, efficient conversion and utilization of energy are achieved. At the same time, through precise pressure regulation and check design, stable delivery and safe use of natural gas are ensured.

[0023] Preferably, in this embodiment, the first pressure-reducing pipeline 2 includes a pipeline a21 and a pipeline b22, and the pipeline a21 is provided with a first shut-off valve 212 and a pressure regulating assembly. Preferably, in this embodiment, the pipeline a21 is also provided with an orifice flowmeter 211 in series for measuring the flow rate of natural gas; an expansion generator 221 is provided in the pipeline b22, the air inlet end of the pipeline a21 is connected to the air outlet end of the air inlet pipeline 1, the air inlet end of the pipeline b22 is connected to the air outlet end of the pipeline a21, and the air outlet end of the pipeline b22 is connected to the air outlet pipeline 4 after passing through the cold energy utilization pipeline, thereby making full use of the high and low pressure difference and cold energy of natural gas and realizing efficient conversion and utilization of energy.

[0024] Preferably, in this embodiment, the first pressure-reducing pipeline 2 also includes a pipeline c23, a pneumatic switch valve 231 is arranged in series in the pipeline c23, a hand wheel is arranged on the pneumatic switch valve 231, the air inlet end of the pipeline c23 is connected to the air outlet end of the pipeline a21, the air outlet end of the pipeline c23 is respectively connected to the first connecting pipeline 6 and the second connecting pipeline 7, the cold energy utilization pipeline is connected to the air outlet pipeline 4 through the first connecting pipeline 6 and the second connecting pipeline 7, and the pipeline c23 is connected to the air outlet pipeline 4 through the second connecting pipeline 7. Under normal circumstances, the hand wheel is driven by a pneumatic device. When the pneumatic device fails or needs manual intervention During the preparation, the operator can manually control the switch of the pneumatic switch valve 231 through the hand wheel. In the absence of an external control signal, the pneumatic switch valve 231 is in a closed state, and the natural gas is connected to the gas outlet pipeline 4 through the pipeline a21 via the pipeline b22, the cold energy utilization pipeline, the first connecting pipeline 6 and the second connecting pipeline 7. The pipeline c23 is used as a backup pipeline. When the pipeline b22 fails, the pneumatic switch valve 231 is controlled to open, and the pipeline a21 is connected to the gas outlet pipeline 4 via the pipeline c23 and the second connecting pipeline 7. When the pipeline b22 fails, the natural gas can still be transported, thereby ensuring the continuity and stability of the natural gas supply.

[0025] Preferably, in this embodiment, a vent valve 71 is provided in the second connecting pipeline 7 to play a role of safety protection. When a fault occurs or maintenance is required, the natural gas pressure in the pipeline is safely released through the vent valve 71 to ensure the personal safety of the staff during the maintenance process and prevent potential dangers caused by natural gas accumulation.

[0026] Preferably, in this embodiment, the pressure regulating assembly includes a pressure regulating valve A213, and the pressure regulating valve A213 is connected in parallel with a pressure regulating valve B214. Specifically, the caliber of the pressure regulating valve A213 is larger than that of the pressure regulating valve B214. The pressure regulating valve A213 has a larger caliber and is mainly used for coarse adjustment. A slight adjustment can cause a large change in the flow rate, so the pressure of the natural gas can be adjusted quickly; while the pressure regulating valve B214 has a smaller caliber and is mainly used for fine adjustment. It can adjust the pressure of the natural gas more precisely. The pressure regulating valve A213 and the pressure regulating valve B214 are mainly used to adjust the natural gas pressure at the input end of the expansion generator 221 to ensure that the pressure of the natural gas reaches a predetermined range before entering the expansion generator 221.

[0027] Preferably, in this embodiment, a pressure gauge A and a visual pressure gauge B are further provided in the second pressure-reducing pipeline 3. The pressure gauge A transmits data remotely to the control room, and the visual pressure gauge B facilitates on-site observation of pressure. Specifically, the pressure gauge A and the visual pressure gauge B are arranged between the pressure regulating valve C32 and the check valve 41. Preferably, in this embodiment, a pressure gauge C and a temperature gauge B are further provided in the pipeline b22 for transmitting data remotely to the control room. Preferably, a pressure gauge D is provided in the pipeline c23 for transmitting data remotely to the control room.

[0028] Preferably, in this embodiment, the expansion generator 221 includes a stator, a rotor, a first impeller, a second impeller and an air suspension bearing. The rotor is arranged in the generator cavity, the rotor is installed with a magnetic steel, the stator is fixed to the inner wall of the generator cavity, the first impeller and the second impeller are respectively arranged at both ends of the rotor, the air suspension bearing is arranged between the first impeller and the second impeller, and a pressure vessel tank 5 is arranged outside the air suspension bearing. The natural gas passes through the filter 11 and the pressure vessel tank 5 in sequence to supply gas to the air suspension bearing. After the gas is supplied, the air suspension bearing is in a suspended state, which greatly reduces the friction loss and improves the energy conversion efficiency. After the natural gas passes through the air suspension bearing, it is connected to the pipeline c23 through the exhaust pipeline of the air suspension bearing. Specifically, the exhaust pipeline of the air suspension bearing is arranged between the pneumatic switch valve 231 and the vent valve 71. The high-pressure natural gas enters the expansion generator 221 to drive the first impeller and the second impeller to rotate, thereby driving the rotor to rotate to generate electricity, and converts the high-pressure natural gas into low-pressure natural gas for output. The generated electrical energy can be effectively utilized, for example, to supply power to the control room.

[0029] The expansion generator 221 is a prior art, and its specific structure can refer to a natural gas static pressure air-floating bearing two-stage expansion generator and power generation system disclosed in a Chinese patent application (publication number: CN111365080B). In view of the fact that the specific structure and working principle of the expansion generator 221 have been disclosed in detail in the prior art, they will not be described in detail in this embodiment.

[0030] Preferably, in this embodiment, the pressure vessel tank 5 is provided with a safety valve 51. Preferably, the pressure vessel tank 5 is also provided with a pressure gauge E to monitor the change of the pressure in the tank in real time. Specifically, the high-pressure side input end of the pressure vessel tank 5 is connected to the second pressure reducing pipeline 3 and is arranged before the second cut-off valve 31, so that natural gas can supply gas to the pressure vessel tank 5 before the pressure is reduced and is not affected by the second cut-off valve 31, thereby ensuring the stability of the gas supply. The pressure vessel tank 5 is also provided with four solenoid valves, which respectively control the inlet and outlet of the pressure vessel tank 5, that is, the high-pressure side input end and the low-pressure side output end. When the pressure in the tank increases, the solenoid valve at the input end is controlled to be cut off, and the solenoid valve at the output end is opened at the same time to release the excess pressure in the tank; conversely, when the pressure in the tank increases, the solenoid valve at the input end is controlled to be cut off, and the solenoid valve at the output end is opened to release the excess pressure in the tank; conversely, when the pressure in the tank increases, the solenoid valve at the input end is controlled to be cut off, and the solenoid valve at the output end is opened to release the excess pressure in the tank; When the pressure drops, the solenoid valve at the input end is controlled to open to allow new high-pressure natural gas to enter the tank, and at the same time, the solenoid valve at the output end is cut off to prevent the pressure from further dropping, so as to maintain the constant pressure state in the tank. Two of the solenoid valves act as backup. When the other two solenoid valves fail or need to be repaired, the backup solenoid valves can be quickly put into use to maintain the stable operation of the pressure vessel tank 5. The low-pressure side output end of the pressure vessel tank 5 is connected to the second connecting pipeline 7. The safety valve 51 and the solenoid valve and other devices work together to achieve precise control of the pressure in the tank to ensure that the pressure is always kept within a safe range. When the pressure in the pressure vessel tank 5 exceeds the preset pressure, the safety valve 51 automatically opens to release part of the pressure to prevent safety accidents caused by excessive pressure. See Figure 2 A drain valve B52 is provided at the bottom of the pressure vessel tank 5 for draining waste.

[0031] The above description is only a preferred embodiment of the present utility model, so all equivalent changes or modifications made according to the structure, features and principles described in the scope of the present utility model patent application are included in the scope of the present utility model patent application.

Claims

1. A natural gas differential pressure radial turbine power generation system, characterized in that: It comprises an air intake pipeline (1), wherein the air intake end of the air intake pipeline (1) is connected to a natural gas transmission pipeline; A first pressure-reducing pipeline (2), wherein a first cut-off valve (212), a pressure-regulating component and an expansion generator (221) are arranged in series in the first pressure-reducing pipeline (2); A second pressure-reducing pipeline (3), wherein a second cut-off valve (31) and a pressure-regulating valve C (32) are serially connected in the second pressure-reducing pipeline (3); The first pressure-reducing pipeline (2) and the second pressure-reducing pipeline (3) are connected in parallel; the air inlet ends of the first pressure-reducing pipeline (2) and the second pressure-reducing pipeline (3) are connected to the air outlet end of the air inlet pipeline (1); the air outlet end of the first pressure-reducing pipeline (2) is connected to the air outlet pipeline (4) via the cold energy utilization pipeline; and the air outlet end of the second pressure-reducing pipeline (3) is connected to the air outlet pipeline (4).

2. A natural gas differential pressure radial turbine power generation system according to claim 1, characterized in that: A filter (11) is arranged in series in the air intake pipeline (1).

3. A natural gas differential pressure radial turbine power generation system according to claim 1, characterized in that: A heat exchanger is arranged in the cold energy utilization pipeline.

4. A natural gas differential pressure radial turbine power generation system according to claim 1, characterized in that: The first pressure-reducing pipeline (2) comprises a pipeline a (21) and a pipeline b (22); the pipeline a (21) is provided with a first shut-off valve (212) and a pressure regulating assembly; the pipeline b (22) is provided with an expansion generator (221); the air inlet end of the pipeline a (21) is connected to the air outlet end of the air inlet pipeline (1); the air inlet end of the pipeline b (22) is connected to the air outlet end of the pipeline a (21); and the air outlet end of the pipeline b (22) is connected to the air outlet pipeline (4) via a cold energy utilization pipeline.

5. A natural gas differential pressure radial turbine power generation system according to claim 4, characterized in that: An orifice flowmeter (211) is also serially connected in the pipeline a (21).

6. A natural gas differential pressure radial turbine power generation system according to claim 4, characterized in that: The first pressure-reducing pipeline (2) further comprises a pipeline c (23), wherein a pneumatic switch valve (231) is arranged in series in the pipeline c (23), and a hand wheel is arranged on the pneumatic switch valve (231); the air inlet end of the pipeline c (23) is connected to the air outlet end of the pipeline a (21); the air outlet end of the pipeline c (23) is respectively connected to a first connecting pipeline (6) and a second connecting pipeline (7); the cold energy utilization pipeline is connected to the air outlet pipeline (4) via the first connecting pipeline (6) and the second connecting pipeline (7); and the pipeline c (23) is connected to the air outlet pipeline (4) via the second connecting pipeline (7).

7. A natural gas differential pressure radial turbine power generation system according to claim 6, characterized in that: The second connecting pipeline (7) is provided with a vent valve (71).

8. A natural gas differential pressure radial turbine power generation system according to claim 4, characterized in that: The pressure regulating assembly comprises a pressure regulating valve A (213), and the pressure regulating valve A (213) is connected in parallel with a pressure regulating valve B (214).

9. A natural gas differential pressure radial turbine power generation system according to claim 8, characterized in that: The diameter of the pressure regulating valve A (213) is larger than the diameter of the pressure regulating valve B (214).

10. The natural gas differential pressure radial turbine power generation system according to claim 1, characterized in that: A check valve (41) is arranged in series in the air outlet pipeline (4).

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